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root/include/net/ip.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. ip_hdrlen
  2. ip_tr_mc_map
  3. ip_reply_arg_flowi_flags
  4. ip_decrease_ttl
  5. ip_dont_fragment
  6. ip_select_ident
  7. ip_select_ident_more
  8. ip_eth_mc_map
  9. ip_ib_mc_map
  10. inet_reset_saddr

/*
 * INET         An implementation of the TCP/IP protocol suite for the LINUX
 *              operating system.  INET is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              Definitions for the IP module.
 *
 * Version:     @(#)ip.h        1.0.2   05/07/93
 *
 * Authors:     Ross Biro
 *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *              Alan Cox, <gw4pts@gw4pts.ampr.org>
 *
 * Changes:
 *              Mike McLagan    :       Routing by source
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 */
#ifndef _IP_H
#define _IP_H

#include <linux/types.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/skbuff.h>

#include <net/inet_sock.h>
#include <net/snmp.h>
#include <net/flow.h>

struct sock;

struct inet_skb_parm
{
        struct ip_options       opt;            /* Compiled IP options          */
        unsigned char           flags;

#define IPSKB_FORWARDED         1
#define IPSKB_XFRM_TUNNEL_SIZE  2
#define IPSKB_XFRM_TRANSFORMED  4
#define IPSKB_FRAG_COMPLETE     8
#define IPSKB_REROUTED          16
};

static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
{
        return ip_hdr(skb)->ihl * 4;
}

struct ipcm_cookie
{
        __be32                  addr;
        int                     oif;
        struct ip_options       *opt;
};

#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))

struct ip_ra_chain
{
        struct ip_ra_chain      *next;
        struct sock             *sk;
        void                    (*destructor)(struct sock *);
};

extern struct ip_ra_chain *ip_ra_chain;
extern rwlock_t ip_ra_lock;

/* IP flags. */
#define IP_CE           0x8000          /* Flag: "Congestion"           */
#define IP_DF           0x4000          /* Flag: "Don't Fragment"       */
#define IP_MF           0x2000          /* Flag: "More Fragments"       */
#define IP_OFFSET       0x1FFF          /* "Fragment Offset" part       */

#define IP_FRAG_TIME    (30 * HZ)               /* fragment lifetime    */

struct msghdr;
struct net_device;
struct packet_type;
struct rtable;
struct sockaddr;

extern int              igmp_mc_proc_init(void);

/*
 *      Functions provided by ip.c
 */

extern int              ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
                                              __be32 saddr, __be32 daddr,
                                              struct ip_options *opt);
extern int              ip_rcv(struct sk_buff *skb, struct net_device *dev,
                               struct packet_type *pt, struct net_device *orig_dev);
extern int              ip_local_deliver(struct sk_buff *skb);
extern int              ip_mr_input(struct sk_buff *skb);
extern int              ip_output(struct sk_buff *skb);
extern int              ip_mc_output(struct sk_buff *skb);
extern int              ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
extern int              ip_do_nat(struct sk_buff *skb);
extern void             ip_send_check(struct iphdr *ip);
extern int              __ip_local_out(struct sk_buff *skb);
extern int              ip_local_out(struct sk_buff *skb);
extern int              ip_queue_xmit(struct sk_buff *skb, int ipfragok);
extern void             ip_init(void);
extern int              ip_append_data(struct sock *sk,
                                       int getfrag(void *from, char *to, int offset, int len,
                                                   int odd, struct sk_buff *skb),
                                void *from, int len, int protolen,
                                struct ipcm_cookie *ipc,
                                struct rtable *rt,
                                unsigned int flags);
extern int              ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
extern ssize_t          ip_append_page(struct sock *sk, struct page *page,
                                int offset, size_t size, int flags);
extern int              ip_push_pending_frames(struct sock *sk);
extern void             ip_flush_pending_frames(struct sock *sk);

/* datagram.c */
extern int              ip4_datagram_connect(struct sock *sk, 
                                             struct sockaddr *uaddr, int addr_len);

/*
 *      Map a multicast IP onto multicast MAC for type Token Ring.
 *      This conforms to RFC1469 Option 2 Multicasting i.e.
 *      using a functional address to transmit / receive 
 *      multicast packets.
 */

static inline void ip_tr_mc_map(__be32 addr, char *buf)
{
        buf[0]=0xC0;
        buf[1]=0x00;
        buf[2]=0x00;
        buf[3]=0x04;
        buf[4]=0x00;
        buf[5]=0x00;
}

struct ip_reply_arg {
        struct kvec iov[1];   
        int         flags;
        __wsum      csum;
        int         csumoffset; /* u16 offset of csum in iov[0].iov_base */
                                /* -1 if not needed */ 
        int         bound_dev_if;
}; 

#define IP_REPLY_ARG_NOSRCCHECK 1

static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
{
        return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
}

void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
                   unsigned int len); 

struct ipv4_config
{
        int     log_martians;
        int     no_pmtu_disc;
};

extern struct ipv4_config ipv4_config;
#define IP_INC_STATS(net, field)        SNMP_INC_STATS((net)->mib.ip_statistics, field)
#define IP_INC_STATS_BH(net, field)     SNMP_INC_STATS_BH((net)->mib.ip_statistics, field)
#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS_BH((net)->mib.ip_statistics, field, val)
#define NET_INC_STATS(net, field)       SNMP_INC_STATS((net)->mib.net_statistics, field)
#define NET_INC_STATS_BH(net, field)    SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
#define NET_INC_STATS_USER(net, field)  SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)

extern unsigned long snmp_fold_field(void *mib[], int offt);
extern int snmp_mib_init(void *ptr[2], size_t mibsize);
extern void snmp_mib_free(void *ptr[2]);

extern struct local_ports {
        seqlock_t       lock;
        int             range[2];
} sysctl_local_ports;
extern void inet_get_local_port_range(int *low, int *high);

extern int sysctl_ip_default_ttl;
extern int sysctl_ip_nonlocal_bind;

extern struct ctl_path net_ipv4_ctl_path[];

/* From inetpeer.c */
extern int inet_peer_threshold;
extern int inet_peer_minttl;
extern int inet_peer_maxttl;
extern int inet_peer_gc_mintime;
extern int inet_peer_gc_maxtime;

/* From ip_output.c */
extern int sysctl_ip_dynaddr;

extern void ipfrag_init(void);

extern void ip_static_sysctl_init(void);

#ifdef CONFIG_INET
#include <net/dst.h>

/* The function in 2.2 was invalid, producing wrong result for
 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
static inline
int ip_decrease_ttl(struct iphdr *iph)
{
        u32 check = (__force u32)iph->check;
        check += (__force u32)htons(0x0100);
        iph->check = (__force __sum16)(check + (check>=0xFFFF));
        return --iph->ttl;
}

static inline
int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
{
        return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
                (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
                 !(dst_metric_locked(dst, RTAX_MTU))));
}

extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);

static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
{
        if (iph->frag_off & htons(IP_DF)) {
                /* This is only to work around buggy Windows95/2000
                 * VJ compression implementations.  If the ID field
                 * does not change, they drop every other packet in
                 * a TCP stream using header compression.
                 */
                iph->id = (sk && inet_sk(sk)->daddr) ?
                                        htons(inet_sk(sk)->id++) : 0;
        } else
                __ip_select_ident(iph, dst, 0);
}

static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
{
        if (iph->frag_off & htons(IP_DF)) {
                if (sk && inet_sk(sk)->daddr) {
                        iph->id = htons(inet_sk(sk)->id);
                        inet_sk(sk)->id += 1 + more;
                } else
                        iph->id = 0;
        } else
                __ip_select_ident(iph, dst, more);
}

/*
 *      Map a multicast IP onto multicast MAC for type ethernet.
 */

static inline void ip_eth_mc_map(__be32 naddr, char *buf)
{
        __u32 addr=ntohl(naddr);
        buf[0]=0x01;
        buf[1]=0x00;
        buf[2]=0x5e;
        buf[5]=addr&0xFF;
        addr>>=8;
        buf[4]=addr&0xFF;
        addr>>=8;
        buf[3]=addr&0x7F;
}

/*
 *      Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 *      Leave P_Key as 0 to be filled in by driver.
 */

static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
{
        __u32 addr;
        unsigned char scope = broadcast[5] & 0xF;

        buf[0]  = 0;            /* Reserved */
        buf[1]  = 0xff;         /* Multicast QPN */
        buf[2]  = 0xff;
        buf[3]  = 0xff;
        addr    = ntohl(naddr);
        buf[4]  = 0xff;
        buf[5]  = 0x10 | scope; /* scope from broadcast address */
        buf[6]  = 0x40;         /* IPv4 signature */
        buf[7]  = 0x1b;
        buf[8]  = broadcast[8];         /* P_Key */
        buf[9]  = broadcast[9];
        buf[10] = 0;
        buf[11] = 0;
        buf[12] = 0;
        buf[13] = 0;
        buf[14] = 0;
        buf[15] = 0;
        buf[19] = addr & 0xff;
        addr  >>= 8;
        buf[18] = addr & 0xff;
        addr  >>= 8;
        buf[17] = addr & 0xff;
        addr  >>= 8;
        buf[16] = addr & 0x0f;
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
#include <linux/ipv6.h>
#endif

static __inline__ void inet_reset_saddr(struct sock *sk)
{
        inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
        if (sk->sk_family == PF_INET6) {
                struct ipv6_pinfo *np = inet6_sk(sk);

                memset(&np->saddr, 0, sizeof(np->saddr));
                memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
        }
#endif
}

#endif

extern int      ip_call_ra_chain(struct sk_buff *skb);

/*
 *      Functions provided by ip_fragment.c
 */

enum ip_defrag_users
{
        IP_DEFRAG_LOCAL_DELIVER,
        IP_DEFRAG_CALL_RA_CHAIN,
        IP_DEFRAG_CONNTRACK_IN,
        IP_DEFRAG_CONNTRACK_OUT,
        IP_DEFRAG_VS_IN,
        IP_DEFRAG_VS_OUT,
        IP_DEFRAG_VS_FWD
};

int ip_defrag(struct sk_buff *skb, u32 user);
int ip_frag_mem(struct net *net);
int ip_frag_nqueues(struct net *net);

/*
 *      Functions provided by ip_forward.c
 */
 
extern int ip_forward(struct sk_buff *skb);
 
/*
 *      Functions provided by ip_options.c
 */
 
extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
extern void ip_options_fragment(struct sk_buff *skb);
extern int ip_options_compile(struct net *net,
                              struct ip_options *opt, struct sk_buff *skb);
extern int ip_options_get(struct net *net, struct ip_options **optp,
                          unsigned char *data, int optlen);
extern int ip_options_get_from_user(struct net *net, struct ip_options **optp,
                                    unsigned char __user *data, int optlen);
extern void ip_options_undo(struct ip_options * opt);
extern void ip_forward_options(struct sk_buff *skb);
extern int ip_options_rcv_srr(struct sk_buff *skb);

/*
 *      Functions provided by ip_sockglue.c
 */

extern void     ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
extern int      ip_cmsg_send(struct net *net,
                             struct msghdr *msg, struct ipcm_cookie *ipc);
extern int      ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
extern int      ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
extern int      compat_ip_setsockopt(struct sock *sk, int level,
                        int optname, char __user *optval, int optlen);
extern int      compat_ip_getsockopt(struct sock *sk, int level,
                        int optname, char __user *optval, int __user *optlen);
extern int      ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));

extern int      ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
extern void     ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 
                              __be16 port, u32 info, u8 *payload);
extern void     ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
                               u32 info);

/* sysctl helpers - any sysctl which holds a value that ends up being
 * fed into the routing cache should use these handlers.
 */
int ipv4_doint_and_flush(ctl_table *ctl, int write,
                         struct file* filp, void __user *buffer,
                         size_t *lenp, loff_t *ppos);
int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
                                  void __user *oldval, size_t __user *oldlenp,
                                  void __user *newval, size_t newlen);
#ifdef CONFIG_PROC_FS
extern int ip_misc_proc_init(void);
#endif

#endif  /* _IP_H */

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